The invention relates to an internal combustion engine with a crankcase, a crankshaft and at least one crankshaft bearing that can be loaded with lubricant for the purpose of mounting the crankshaft in the crankcase.
In the internal combustion engines known from the prior art, the crankshaft bearings are loaded with lubricant from only a single lubricant feed system when the internal combustion engine is running.
Owing to this unilateral lubricant loading there are dynamically adverse effects that drastically limit the flow of lubricant to both the opposite bearing area and the connecting rod bearings. Consequently, the amount of lubricant at the crankshaft bearing is wholly inadequate, so that there is an undue rise in temperature. In addition, there is also a sharp drop in the pressure at the crankshaft bearing, so that the lubricant pressure that prevails at the bearing points that are to be supplied thereafter is now even lower. Therefore, the use of very high grade and, thus, expensive bearing materials is often necessary.
Based on this prior art, the object of the invention is to provide an internal combustion engine that can feed a greater quantity of lubricant to the crankshaft bearing when the internal combustion engine is running, that can avoid an undesired sharp drop in the pressure of the lubricant at the crankshaft bearing, and that can, therefore, use more cost-effective bearing materials.
This engineering object is achieved with an internal combustion engine comprising a crankcase, a crankshaft, and at least one crankshaft bearing that can be loaded with lubricant for the purpose of mounting the crankshaft in the crankcase. The at least one crankshaft bearing comprises at least two separate lubricant feed systems.
Preferably, the at least two separate lubricant feed systems are distributed at least approximately uniformly over the circumference of the crankshaft bearing. This strategy makes it possible to achieve a uniform and/or symmetrical lubricating film characteristic when the internal combustion engine is running.
According to a preferred embodiment, in the case of an internal combustion engine, wherein the at least one crankshaft bearing comprises at least two bearing shells, each bearing shell is assigned a lubricant feed system. In this respect it is expedient to arrange the lubricant feed system at least approximately in the center of the bearing shell in the circumferential direction of the crankshaft.
It is regarded as very advantageous if each lubricant feed system is assigned a lubricant channel. This feature ensures an independent and/or sufficient supply of lubricant to the lubricant feed systems.
In an internal combustion engine, wherein the crankcase comprises an upper part and a bottom part, it has proven to be practical if the crankcase upper part has at least one lubricant channel for loading a lubricant feed system of the at least one crankshaft bearing with lubricant and if the crankcase bottom part has at least one lubricant channel for loading a lubricant feed system of the same crankshaft bearing with lubricant.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of an especially preferred embodiment when considered in conjunction with the accompanying drawings, where an internal combustion engine housing with a crankshaft and a crankshaft bearing that can be loaded with lubricant are shown as an example.